摘要

      欧洲养殖业，即鳟鱼养殖场，在传播抗生素耐药性和/或人畜共患病原体方面的影响几乎没有得到解决。此外，水产养殖的污染源和细菌传播途径还很少被探索。在这项研究中，我们评估了葡萄牙陆地密集型虹鳟养殖场和零售市场鳟鱼对沙门氏菌和携带临床相关抗生素抗性基因（ARGs）的细菌传播的贡献，以及这些污染物的可能来源的进水和饲料。采用培养法和分子分析法对53个养殖场样品（上游/下游水体和沉积物、水槽和鳟鱼）和25个市场鲑鱼进行了分析。质粒介导的喹诺酮类耐药（PMQR）基因存在于21%（n = 11/53）的样品（水/沉积物/饲料/鳟鱼）、所有采集点（上游/内部/下游槽）和季节中以及12%（n = 3/25）的市售鳟鱼（3家超市）中。在肠杆菌科和嗜水气单胞菌中检测到PMQR基因（qnrS1-S2-S3、qnrB7-B19、qnrD1、oqxAB）。在一个渔场的所有采样点检测到一株产超广谱β-内酰胺酶SHV-12的大肠杆菌。在两个农场（水/沉积物上游/罐内）的26%（n = 14/53）样本中检测到沙门氏菌（4种血清型，包括S.Newport-ST118）。未检测到临床相关的质粒介导的大肠杆菌素耐药mcr基因。然而，在染色体pmrA和pmrB基因中发现了新突变的耐大肠杆菌素的Abony菌株。鳟鱼养殖场上游和槽内水体中的沙门氏菌和产生SHV-12的大肠杆菌（PFGE/MLST）相同，表明鳟鱼养殖场进水是致病菌和精氨酸污染的重要来源。这些结果突出表明，有必要确定欧盟供水鱼场的微生物标准，并制定监测和控制战略，以限制与这一全球增长最快的食品部门相关的细菌传播。

      The impact of European aquaculture, namely trout farms, in the spread of antibiotic resistance and/or zoonotic pathogens has been scarcely addressed. Moreover, aquaculture contamination sources and bacterial dissemination routes have been barely explored. In this study, we assessed the contribution of Portuguese land-based intensive rainbow trout farms and retailed market trout to the spread of Salmonella and bacteria carrying clinically-relevant antibiotic resistance genes (ARGs) as well as inflow water and feed as possible sources of those contaminants. Cultural and molecular methods were used to analyse 53 fish farm samples (upstream/downstream water and sediments, tanks and trout) and 25 marketed trout. Plasmid-mediated quinolone resistance (PMQR) genes were found in 21% (n = 11/53) of samples (water/sediment/feed/trout), from all collection points (upstream/within/downstream tanks) and seasons, as well as in 12% (n = 3/25) of marketed trout (3 supermarkets). PMQR genes (qnrS1-S2-S3, qnrB7-B19, qnrD1, oqxAB) were detected in Enterobacteriaceae or Aeromonas hydrophila. An E. coli strain producing extended-spectrum-beta-lactamase SHV-12 was detected in all sampled points of a fish farm. Salmonella (4 serotypes, including S. Newport-ST118) was detected in 26% (n = 14/53) of the samples from both farms (water/sediment upstream/within tanks). The clinically-relevant plasmid-mediated colistin resistance mcr genes were not detected. However, colistin resistant S. Abony with new mutations in the chromosomal pmrA and pmrB genes was observed. Identical Salmonella and SHV-12-producing E. coli strains (by PFGE/MLST) in water upstream and within trout tanks points to inflow-water of trout farms as an important source of pathogenic bacteria and ARG contamination. These results highlight the need to define microbiological standards for water supplying fish farms in the EU and to establish surveillance and control strategies to limit bacterial transmission associated with this fastest growing food sector worldwide.

        https://www.sciencedirect.com/science/article/pii/S0048969718322198?via%3Dihub